First time grower, help me choose strain!

You can't go wrong with Northern Lights ;P

With having grown much more difficult plants from seed in the past, you should feel confident in growing any of them or all of them. You aren't a newb if you started cacti from seed or clone. First thing you should learn is that what you learned for other plants applies, if someone tells you something that goes against what you have learned on other plants, highly doubt what they have said, even if they seem to know what they are talking about.